为推广直径10mm以内的螺栓紧固件在钢-木组合结构中的应用，研究螺栓横向排数、螺栓直径和螺栓纵向间距对钢-木组合梁弯曲性能的影响。通过设计一种下部是工字钢梁、上部是木板、上下部由螺栓连接的组合梁，对8根试验梁进行三分点弯曲荷载试验，分别观察其破坏模式、跨中挠度变化、跨中截面应变和梁端部钢-木交界面滑移效应，分析不同螺栓参数对钢-木组合梁抗弯力学性能的影响。试验结果表明：钢-木组合梁的主要破坏模式为：组合梁跨中挠度达到跨度的1/27时，发生变形破坏；组合梁具有较高的抗弯承载力与位移延性系数，各试件钢-木交界面最大相对滑移为2mm~6mm；螺栓布置参数中，螺栓纵向间距对对组合梁跨中钢-木交界面的应变差影响最大，螺栓直径影响较小；提出了钢-木组合梁螺栓面积比的概念，即螺栓总面积与木板受压面积的比值，随螺栓面积比的增加，尽管位移延性系数减小，但试件抗弯承载力明显增长、交界面最大滑移逐步减小。通过合理的螺栓面积比范围可快速计算出螺栓的用量范围，为此类钢-木组合梁的实际应用提供设计参考。

In order to promote the application of bolt fasteners with diameters of up to 10 mm in steel-wood composite structures, the effects of the number of transverse rows of bolts, bolt diameters and longitudinal spacing of bolts on the bending performance of steel-wood composite beams were investigated. By designing a composite beam with a I-steel beam at the lower part and wooden board at the upper part, the upper and lower parts connected by bolts. a three-point bending load test was carried out on 8 test beams, to observe the failure mode, mid-span deflection variation, mid-span section strain and slip effect at the steel-wood intersection at the end of the beam respectively, to investigate the effect of different bolt parameters on the flexural mechanical properties of the steel-wood composite beam. The test results showed that the main damage mode of the steel-wood combination beam is the mid-span deflection up to 1/27 of the calculated span,resulting in deformation damage; Composite beams had high flexural capacity and ductility coefficient. The maximum relative slip at the steel-wood interface of each specimen was 2mm~6mm; Among the parameters of bolt arrangement, the longitudinal spacing of bolts had greater influence on the strain difference at the steel-wood interface in the span of the composite beam, while the bolt diameter had less influence. The concept of bolt area ratio of steel-wood composite beam was proposed, i.e. the ratio of total bolt area to compressive area of wood board. With the increase of the bolt area ratio, the flexural load capacity of the specimen increases significantly and the maximum slip at the intersection decreases gradually, although the displacement ductility coefficient decreases. The range of bolt usage can be quickly calculated by optimum the reasonable range of bolt area ratio, which provides design reference for practical application of such steel-wood composite beam.

湖南省教育厅项目(20K126)；国家国际科技合作专项(2014DFA53120)